The Ension pediatric cardiopulmonary assist system (pCAS) has been designed and developed as a next-generation extracorporeal membrane oxygenation (ECMO) - also called extracorporeal life support (ECLS) - system that provides increased functionality and blood compatibility. The intended use of the pCAS is to provide partial or complete cardiopulmonary support to patients from 2 kg to 25 kg for periods of up to two weeks using a single disposable blood-contacting pump-oxygenator. The system has been specifically designed to accommodate extended support beyond this two-week period by rapid change-out of the pump-oxygenator in a procedure that can be completed in less than five minutes. The system offers key advantages over currently available systems, specifically improved blood compatibility, smaller surface area and priming volume, rapid deployment, and a compact configuration that facilitates parent-child bonding and patient transport. The pCAS system consists of a pump-oxygenator, a control console, and ancillary components that include venous and arterial cannulae and a bubble trap. The pCAS pump-oxygenator is a compact device consisting of a centrifugal impeller directly integrated with a blood oxygenator via a turning diffuser. The oxygenator is comprised of hollow fiber membranes (Celgard polypropylene microporous knitted array) incorporating a heparin-based engineered surface specifically designed to enhance blood compatibility. The pCAS control console functionality includes regulation of pump speed, display of all operational parameters, monitoring for fault conditions, display of alarms, and control of purge fluid supplied to the blood seal. The control console incorporates an internal backup battery capable of providing over two hours of continuous operation should AC power be lost or during patient transport. Prototype pCAS pump-oxygenators and control consoles have been fabricated and tested extensively during the development phase of the pCAS project (primarily supported by NIH Pediatric Circulatory Support contract HHSN268200448189C beginning in April 2004 and ongoing). Candidate designs for the integrated pump-oxygenator and control console, as well as subsequent refinements, were guided by functionality, biocompatibility, clinical, and cost requirements as well as test data, formal hazards analysis, human factors evaluations, computational fluid dynamics (CFD) analyses, and reliability considerations. Manufacturing processes have been established, refined, and validated as part of the product development and prototype production processes. Ension is prepared to assemble and test all necessary pCAS system components under a Quality System compliant with ISO 13485 as well as the design control regulations articulated in 21 CFR 820.30. This includes the continued use of in-depth risk and reliability analysis, management, and mitigation. Ension's pCAS system has been extensively tested in vitro and in vivo during development. In vitro data have demonstrated the pCAS pump-oxygenator's ability to achieve required blood flow rates and pressures and to exchange oxygen and carbon dioxide. Additional in vitro data have confirmed minimal blood damage as evidenced by low levels of red cell, white cell, and platelet consumption, significant improvement in plasma leakage over currently available hollow fiber membrane oxygenators, and improvement in blood compatibility. Ension has conducted in vivo system testing in piglets demonstrating that the pCAS system provides appropriate hemodynamic support for the small patients in the target population and in calves demonstrating longer-term device functionality and blood compatibility.